Insulin that "feels" blood sugar – type 1 diabetes solution?

Approximately 9 million people live with type 1 diabetes. This is what their typical daily routine might look like: At 7:00 a.m., wake up and check blood sugar; at 9:00 a.m., eat breakfast, calculate carbohydrates, check blood sugar; at 11:30 a.m., eat lunch and take insulin; at 1:00 p.m., eat a snack, calculate carbohydrates, take insulin; repeat every 1-2 hours, depending on blood sugar levels.

"With type 1 diabetes you have to think about every decision you make, right from the moment you wake up," says Grace Bennett, who works for the type 1 diabetes charity Breakthrough T1D. 

Grace was diagnosed with type 1 diabetes when she was 12.

"If I want to eat a snack, I have to ask myself if I want a snack badly enough," she explains. "Is my blood sugar at a point where I really should be having a snack, am I eating it because I am hungry?"

The bodies of people with type 1 diabetes (T1D) cannot produce insulin, so they must regularly inject themselves with a synthetic version of the hormone. Living with the daily demands of type 1 diabetes includes closely monitoring blood sugar levels and carefully regulating insulin intake.

But what if a single dose of insulin just once a week were enough? Or if the insulin itself could "sense" blood sugar levels, making hourly check-ins a thing of the past? 

Six new research projects in universities in the US, China and Australia are trying to achieve just this, as researchers continue exploring newer and "smarter" insulin composites.

What is type 1 diabetes?

Blood sugars, also called blood glucose, are the primary source of energy in the body. 

When you eat food, the body breaks down most of it into glucose, which is released into the bloodstream. When glucose levels go up, the pancreas releases the hormone insulin. It helps glucose to be used as energy by your cells.

People with type 1 diabetes have a pancreas that either cannot produce insulin, or produces very little of it. No or low insulin prevents the uptake of glucose in the body's cells, causing it to build up in the bloodstream. 

High levels of glucose dangerous. If left untreated, they can lead to heart disease, kidney problems, extreme fatigue and other serious conditions. 

In 2019, diabetes was the direct cause of 1.5 million deaths globally.

"You have this thing that runs essentially your entire life. At the same time, it's also a largely invisible illness, unless you see my insulin pump or my continuous glucose monitor," says Grace.

Why do we need better insulin?

Glucose levels in the blood change constantly. They go up and down depending on your stress levels, whether you have exercised, what foods you have eaten, and the levels of other hormones in your body. Even the weather can affect them. 

"Insulin-wise, food-wise, exercise-wise, I can be doing things the exact same way as I did the day before. But my blood sugars might look vastly different, depending on hormones or exercise. It's not something you can ever not be thinking about," Grace explains.

This makes it very hard for the bodies of people with type 1 diabetes to maintain stable blood sugar levels, even with the newest technology available to monitor glucose and administer insulin when needed.

"There have been times where I've had to say to myself that I literally don't have an option. There is no 'Oh, I'll skip my medicine because I don't like the way it makes me feel' or 'I need a day off.' That's gonna end in an ER visit and possibly worse," she adds.

What could 'smart' insulin look like?

Glucose-responsive insulin (or "smart" insulin) promises an end to the constant glucose monitoring that can be so burdensome for many people with T1D.

Instead, patients could swallow a pill or inject insulin once every morning. The smart insulin then remains inactive in the body until blood sugar levels rise. Once the smart insulin detects a change in glucose levels, it can "wake up" and stabilize them before returning to an inactive state.

The effect would be similar to that produced by a functioning pancreas, which only releases insulin when it's needed in the body. 

For Grace, the possibility of using glucose-responsive insulin not only would impact the physical aspect of T1D, but ease the mental burden that comes with upholding strict daily routines.

"If I knew I was using an insulin that could sense what my blood sugar was and respond, that is less time that I have to think about what I'm doing. I could, for example, go for a walk around the block without having a packet of honey with me just in case I go low," Grace adds.

Are we there yet?

Although research on smart insulin is still in its early stages, the hope is that one day they can take the pressure off people who currently have to monitor their blood glucose levels multiple times a day.

The Type 1 Diabetes Grand Challenge is funding six projects involving universities from the United States, China and Australia with more than €3 million (£2.7 million) for smart insulin development.

One of the projects, from Stanford University in the US, aims to develop an ultra-fast insulin which is released more quickly into the bloodstream, mimicking a type of insulin cone snails use to immobilize prey. 

Another project, from Zhejiang University in China, hopes to reduce insulin injections to once a week by fine-tuning how the hormone is released from a reservoir in the body.

"If you told 12-year-old me that one day they would be researching insulins that might have the capability to behave like this in the human body, I'd be like 'No way, that's insane.'" Grace says. "The progress that's been made in researching these novel insulins or management tools is truly incredible."

Edited by: Derrick Williams